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Guanetal.
BMC Medical Research Methodology (2023) 23:281
https://doi.org/10.1186/s12874-023-02095-0
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BMC Medical Research
Methodology
The methodological quality assessment
ofsystematic reviews/meta-analyses ofchronic
prostatitis/chronic pelvic pain syndrome using
AMSTAR2
Xin Guan1,2†, Yongfeng Lao1,2†, Jian Wang1,2†, Yanan Wang1,2, Yanan Bai1,3, Xiaolong Li1,2, Shuai Liu1,2,
Zewen Li1,2, Fuhan Li1,2 and Zhilong Dong1,2*
Abstract
Background This study aimed to assess the methodological quality of the systematic reviews/meta-analyses (SRs/
MAs) of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) using A Measurement Tool to Assess systematic
Reviews (AMSTAR2) and to explore the potential influencing factors.
Methods PubMed, EMBASE and Cochrane Library databases were searched for relevant studies. AMSTAR2 was used
for evaluating the methodological quality of eligible SRs/MAs. Differences between methodological characteristics
of SRs/MAs were compared using chi-square tests. The intra-class correlation coefficient (ICC) was used to assess
reviewer agreement in the pre-experiment. Multivariate regression analysis was used to identify potential factors
affecting methodological quality.
Results A total of 45 SRs/MAs were included. After AMSTAR2 evaluation, only two (4.4%) of 45 SRs/MAs were moder-
ate, three (6.7%) were rated as low quality, and the remainder 40 (88.9%) were rated as critically low quality. Among
the 16 items of AMSTAR2, item 3 and item 10 had the poorest adherence. Item 4 received the most significant num-
ber of "Partial Yes" responses. Univariable analysis indicated that there were significant differences in methodologi-
cal quality in SRs between different continents (P = 0.027) as well as between preregistered SRs and those that were
not (P = 0.004). However, in multivariate analysis, there was no significant association between methodological quality
and the following research characteristics: publication year, continent, whether reporting followed Preferred Report-
ing Items for Systematic Reviews (PRISMA), preregistration, funding support, randomized controlled trials (RCT) enroll-
ment, whether SR was published in the Cochrane Database of Systematic Reviews (CDSR), and whether with meta-
analysis. Additionally, subgroup analysis based on interventional SRs/MAs showed that continent was independently
associated with the methodological quality of SRs/MAs of CP/CPPS via univariable and multivariate analysis.
Conclusions Our study demonstrates that the methodological quality of SRs/MAs of CP/CPPS was generally poor.
SRs/MAs of CP/CPPS should adopt the AMSTAR2 to enhance their methodological quality.
†Xin Guan, Yongfeng Lao and Jian Wang contributed equally to this work and
share the first authorship.
*Correspondence:
Zhilong Dong
dzl19780829@163.com
Full list of author information is available at the end of the article
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Guanetal. BMC Medical Research Methodology (2023) 23:281
Keywords Systematic review, Meta-analysis, Chronic prostatitis/chronic pelvic pain syndrome, AMSTAR2,
Methodological quality, Cross-sectional study
Background
Chronic prostatitis/chronic pelvic pain syndrome (CP/
CPPS) is the most common genitourinary disorder in
men under 50years of age [1], and it has been reported
that 35–50% of men in all age groups will be affected by
symptoms suggesting prostatitis during their lifetime [2].
In addition, the prevalence of CP/CPPS is estimated to
range from 8.4% to 25% on different continents [3]. Based
on the classification system of prostatitis syndromes
established by the National Institute of Health (NIH) in
1999, CP/CPPS can be divided into two subtypes: IIIA
(inflammatory), and IIIB (Noninflammatory), account-
ing for about 90–95% of all prostatitis cases [4]. e
manifestations of CP/CPPS were heterogeneous, mainly
including urogenital pain, lower urinary tract symptoms
(LUTS), psychological problems, and sexual dysfunction
[5, 6]. e disorder not only impairs the quality of life
(QOL) of patients but often leads to severe psychosocial
and economic burdens [3, 6].
Although many clinical trials, as well as systematic
reviews/meta-analyses (SRs/MAs) of CP/CPPS, have
been published and various treatment options have
been recommended, there is still no ideal and stand-
ardized management for CP/CPPS up to now [7–10].
erefore, CP/CPPS is still a massive challenge in clini-
cal practice. e reason for this problem is that, on
the one hand, the etiology and pathophysiology of CP/
CPPS remain unclear; on the other hand, it may be due
to the poor quality of clinical evidence of CP/CPPS,
which leads to their limited reliability and usefulness
in guiding clinical practice. Primary studies, especially
randomized controlled trials (RCT), often provide the
most direct and powerful evidence in medical prac-
tice, making them the "gold standard" for assessing the
effectiveness and safety of medical interventions [11]. A
recent study suggested that the quality of RCT reports
of CP/CPPS needs to be further improved and that the
results of RCT of CP/CPPS should be treated with cau-
tion [12]. Additionally, the SRs/MAs are considered
vital evidence for the development of clinical practice
guidelines and can inform healthcare policy as well as
clinical decision-making [13, 14]. As with all original
research, SRs should be also assessed for their method-
ological rigor, as only high-quality SRs/MAs that follow
specific guidelines and report normatively can provide
convincing results and conclusions [15, 16]. Research-
ers have developed several assessment tools to assess
the methodological quality of SRs/MAs, among which
A Measurement Tool to Assess Systematic Reviews
(AMSTAR2) is one of the most studied and widely used
tools [17]. AMSTAR was developed and validated in
2007, but it could only be used to evaluate RCT-based
SRs/MAs initially [18]. As a new version, AMSTAR2
enables a more detailed and reproducible assessment of
the quality of SRs/MAs of randomized controlled tri-
als (RCT) and non-RCTs [17]. Compared with other
quality assessment tools, such as the risk of bias in sys-
tematic reviews (ROBIS) [19], AMSTAR2 takes into
account more information related to methodological
quality [17]. erefore, AMSTAR2 has become a stand-
ard tool for evaluating the methodological quality of
SRs/MAs.
To our knowledge, no studies evaluating the meth-
odological quality of SRs/MAs of CP/CPPS have been
reported. erefore, the primary aim of this study was
to assess the methodological quality of SRs/MAs of CP/
CPPS using AMSTAR2 and explore potential risk factors
associated with the methodological quality of SRs/MAs
of CP/CPPS. is might provide an important reference
for follow-up studies and optimize the production and
dissemination of clinical evidence for CP/CPPS.
Methods
Protocol andregistration
is study has been prospectively registered on the
PROSPERO platform [20, 21], and the registration num-
ber is CRD42022343957 while the full registration docu-
ment can be accessed from the official website [22].
Search strategy
We comprehensively searched the literature in PubMed,
EMBASE, and the Cochrane Library database for SRs/
MAs of CP/CPPS from their inception to December 31,
2022. e following keywords were used as search terms:
(Prostatitis OR Prostatitides OR Chronic Prostatitis with
Chronic Pelvic Pain Syndrome OR Chronic Prostatitis/
Chronic Pelvic Pain Syndrome OR Chronic Pelvic Pain
Syndrome OR Chronic Prostatitis OR Chronic Prosta-
titides OR CP/CPPS OR CPPS) AND (Meta-Analysis
OR Meta Analyses OR Network Meta-Analysis OR Sys-
tematic Review OR System Review OR Evidence based
review OR Evidence-based review OR System evaluation
OR Systematic evaluation). e full search strategy was
available in the supplementary file (Additional file1).
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Guanetal. BMC Medical Research Methodology (2023) 23:281
Eligibility criteria
e inclusion criteria were as follows: (1) populations:
the participants who met criteria for CP/CPPS categories
IIIA or IIIB according to the National Institutes Health
classification [4], regardless of complications, no restric-
tions on age, race, the source of cases, or onset time; (2)
study designs: systematic reviews with or without meta-
analysis; (3) language: the studies published in Chinese
or English; (4) interventions: all treatments or interven-
tions for CP/CPPS that were included in the systematic
reviews; (5) comparators: all controls involved in the
systematic reviews, such as placebo control, etc.; (6) pub-
lication language: Chinese or English. e exclusion cri-
teria were as follows: (1) conference abstracts, editorials
and expert opinions, letters, conference proceedings, and
case reports; (2) the subjects included in the study were
not human; (3) the full text could be found and unable
to provide the required data. ere was a certain situa-
tion that one SR published in the Cochrane Library had
also been published in another journal, we only included
the SR published in the Cochrane Library because it was
more comprehensive [23].
Data selection
Endnote X9, the literature management software, was
used to manage the literature search records. Two
trained researchers (YNB, SL) independently reviewed all
the titles and abstracts of sources for preliminary inclu-
sion against the preset eligible criteria. en the full text
of the potentially eligible articles left at the above stage
was checked for final inclusion by two trained research-
ers (YNB, SL) independently, and the reasons for article
exclusion were recorded. To ensure the quality of litera-
ture screening and reduce the risk of bias, the screening
results of each author should be blind compared with
other authors. A third researcher (ZLD) resolved any
disagreements arising during the pairing process through
negotiation and arbitration.
Data extraction
We designed a standardized form to extract all avail-
able data, and the two trained researchers (JW, YNW)
independently extracted the data. e following data
were extracted from each eligible literature: (1) general
characteristics: first author, publication year, country of
correspondence author, number and type of included
studies, sample size, whether with meta-analysis, fund-
ing support, presence or absence of preregistration
(detailed platform extracted), and reporting criteria
referenced by the study (such as Preferred Reporting
Items for Systematic Reviews (PRISMA), Joanna Briggs
Institute (JBI) Critical Appraisal Tool, and Cochrane
Handbook for systematic reviews [24–26]), etc.; (2)
participants’ details: category of CP/CPPS, diagnos-
tic criterion, etc.; (3) intervention/control: interven-
tion/control measures, drug doses, duration, routes
of administration, etc.; (4) outcome indicators: scores
of scales such as National Institutes of Health chronic
prostatitis symptom index (NIH-CPSI) scores, Inter-
national prostate symptom score (IPSS), etc., the clini-
cal effective rate of CP/CPPS, International Index of
Erectile Function (IELT), etc. A third researcher (ZLD)
resolved any disagreements arising during the pairing
process through negotiation and arbitration.
Methodological quality assessment
Two trained researchers (YFL, XG) independently
assessed the methodological quality of all eligible lit-
erature via the AMSTAR2 tool. AMSTAR2 tool consists
of 16 items, and researchers need to evaluate each item
with Yes, Partial Yes (PY), or No. When the evaluation
criteria of the item are fully met, the item should be
rated as a “Yes”. PY indicates that the systematic review
only partly complied with the standard for the given
item. If no relevant information is reported to rate
an item in the system reviews, the evaluation is “No”.
Furthermore, seven (items 2, 4, 7, 9, 11, 13, and 15) of
16 items are considered critical domains, correspond-
ing to the comprehensiveness of the literature search,
preparation for the review, eligibility criteria, Risk of
Bias (RoB) analysis and interpretation, appropriateness
of meta-analysis, and potential impact of publication
bias [15, 17]. Based on weaknesses identified in critical
and non-critical items, AMSTAR2 classifies the overall
confidence of the results of included systematic reviews
into four levels: high, moderate, low, and critically
low. e supplementary file (Additional files 2 and 3)
showed details of the items in the AMSTAR2 tool and
the definition of the four quality classifications. A third
reviewer (ZLD) settled any disagreements between
reviewers through consultation and arbitration.
Consistency evaluation
e researchers who assessed the methodological qual-
ity of included studies based on the AMSTAR2 tool have
undergone systematic training at the Evidence-Based
Medicine Center of Lanzhou University. e articles
included in this study were evaluated afterward when the
two researchers reached a good agreement (at least 90%)
in the pre-experiment. We used the intraclass correlation
coefficient (ICC) to assess the consistency of quantitative
measurements in the pre-experiment. e ICC value for
the overall score was 0.920.
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Guanetal. BMC Medical Research Methodology (2023) 23:281
Data analysis
Stata 14.0 was used for statistical analysis. e continu-
ous variables were described with the mean ± standard
deviation. e categorical variables were described by
frequencies and percentages. In this study, we explored
the impact of the following factors on the quality of the
included SRs/MAs of CP/CPPS: (1) publication year
(year in which the included SRs/MAs of CP/CPPS were
published); (2) continent (classified based on the country
where the first corresponding author is located); (3) fol-
lowing PRISMA; (4) preregistration (preregistration on
any platform such as PROSPERO and Cochrane library,
etc. was considered as Yes, otherwise as No); (5) fund-
ing support; (6) whether Cochrane Database of System-
atic Reviews (non-CDSR, or CDSR); (7) RCT enrollment
(non-RCTs, only RCTs, or RCTs and non-RCTs); (8)
whether meta-analysis was performed (without a meta-
analysis, or with a meta-analysis), as previous studies
have suggested that these factors may be potential factors
affecting the methodological quality of SRs/Mas [15, 23,
27–32]. Chi-square tests or Fisher’s exact tests were used
to compare SRs/MAs characteristics based on AMSTAR2
appraisal outcomes. Multiple regression was employed to
assess potential factors that may have an impact on the
methodological quality of SRs/MAS of CP/CPPS, and
variance inflation factors (VIFs) were utilized to test for
multicollinearity among explanatory factors. Subgroup
analysis was conducted based on the type of SRs (inter-
ventional and non-interventional). P-value ≤ 0.05 was
considered significant for all statistical tests.
Results
Literature search
e process of the literature search and selection was
presented in Fig.1. A total of 573 articles were obtained
after retrieval while 406 articles were left after removing
duplicates. en 299 articles were excluded after review-
ing the titles and abstracts, leaving 107 records for full-
text screening. Finally, 62 records were further excluded
and 45 SRs/MAs were included in our study [6, 7, 33–75].
A list of the articles excluded after the screen of the full
text was provided in supplement files (Additional file4).
Fig. 1 The details of the literature selection process
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Guanetal. BMC Medical Research Methodology (2023) 23:281
Characteristics ofsystematic reviews
e detailed characteristics of all included SRs/MAs are
listed in Table1. 45 SRs/MAs were published between
1999 and 2022, with no SRs/MAs of CP/CPPS published
in 2001, 2003–2005, or 2009–2010, but relevant literature
was published almost every year after 2010 (Fig.2). us,
2010 was regarded as a time node and used for subse-
quent univariable and multivariable analysis since there
was a burst of relative literature in the field after 2010. 44
studies enrolled patients diagnosed with CP/CPPS, while
one enrolled patient diagnosed with CP/CPPS also had
sexual dysfunction (SD). e minimum and maximum
number of trials in the included SRs/MAs were 1 and 99
respectively, and the minimum and maximum number
of participants in included studies were 54 and 44,650
respectively. e included SRs/MAs are mainly from five
continents: Asia (n = 29, 64.4%), Europe (n = 6, 13.4%),
North America (n = 8, 17.8%), and South America(n = 2,
4.4%). More than half of the SRs/MAs originated from
China, followed by the United States (USA). Forty (88.9%)
SRs/MAs were non-Cochrane reviews, and five (11.1%)
SRs/MAs were Cochrane reviews. Nearly two-thirds
(n = 29, 64.4%) of the SRs/MAs enrolled only RCTs, five
(11.1%) SRs/MAs only included non-RCTs and approxi-
mately a quarter (n = 11, 24.4%) of SRs/MAs enrolled not
only RCTs but also non-RCTs. Of all the included studies,
only PRISMA was mentioned as a reporting standard for
article publication. Specifically, two-thirds (n = 30, 66.7%)
of the SRs/MAs followed the PRISMA, while the remain-
ing did not indicate which reporting standard was refer-
enced. Also, considering the authority and widespread
use of PRISMA in SRs, we included whether PRISMA
was followed or not as one of the independent variables
in the subsequent risk factor analysis. Over half (n = 24,
53.3%) of the SRs/MAs received funding support. About
one-third (n = 16, 35.6%) of the SRs/MAs were preregis-
tered on platforms. irty-six included studies (80.0%)
were systematic reviews with a meta-analysis. irty-
eight studies (84.4%) were interventional SRs/MAs. In
addition, the intervention and control measures of the
included studies were shown in Additional file5.
Methodological quality
e evaluation results of all AMSTAR2 items assess-
ment for each study are presented in Table2 while the
result distribution of each item of AMSTAR2 was shown
in Fig.3. None of the included studies was classified as
high quality, two (4.4%) SRs/MAs were rated as moder-
ate quality, three (6.7%) were assessed as low-quality,
and remaining forty (88.9%) were assessed as low qual-
ity. e AMSTAR2 adherence varies widely among the
items. Item 1 (PICO: populations, interventions, com-
parisons, and outcomes) has the best adherence in all
included SRs/MAs, followed by item 16 (conflict of inter-
est). Item 3 (selection of the study designs) and item 10
(funding reported for individual studies) showed the
poorest adherence in the SRs/MAs. e most PY rat-
ings were given on item 4 (comprehensiveness of litera-
ture strategy). Among the seven essential items, the most
frequently lacking items were as follows: item 7 (n = 38,
84.4%), lack of excluded trials list and reasons for exclu-
sion), item 13 (n = 33, 73.3%), lack of adequate discus-
sion of the impact of risk of bias on study results), item 2
(n = 30, 66.7%), lack of registration before the commence-
ment of the review).
Univariable analysis
We identified the association between each potential fac-
tor and methodological quality by Chi-square tests or
Fisher’s exact tests. e methodological quality of SRs/
MAs differed significantly in the continent (P = 0.027)
and preregistration (P = 0.004). However, no significant
differences were observed in publication year (P = 1.000),
PRISMA (P = 0.589), funding support (P = 0.791),
whether CDSR (P = 0.087), RCT enrollment (P = 0.590),
and meta-analysis (P = 0.431). e detailed results are
displayed in Table3.
Multivariate analysis
No significant factors related to the methodological qual-
ity of systematic reviews were observed in multivari-
ate analysis. SRs/MAs from Asia were similar to those
from Europe (coefficient, 0.481; 95% CI, -0.040 to 1.002;
P = 0.069), North America (coefficient, -0.064; 95% CI,
-0.557 to 0.429; P = 0.793) and South America (coef-
ficient, -0.299; 95% CI, -1.315 to 0.718; P = 0.554). e
methodological quality of SRs/MAs that did not include
RCTs was similar to those that included only RCTs (coef-
ficient, -0.176; 95% CI, -0.624 to 0.272; P = 0.430), and
those that included RCTs and non-RCTs (coefficient,
-0.272; 95% CI, -0.808 to 0.264; P = 0.309). Furthermore,
no significant differences of the methodological qual-
ity of SRs/MAs were observed in the publication year
(coefficient, 0.333; 95% CI, -0.159 to 0.826; P = 0.117),
PRISMA (coefficient, -0.105; 95% CI, -0.510 to 0.300;
P = 0.602), preregistration (coefficient, 0.231; 95% CI,
-0.138 to 0.600; P = 0.212), funding support (coefficient,
-0.059; 95% CI, -0.416 to 0.297; P = 0.737), whether CDSR
(coefficient, 0.532; 95% CI, -0.193 to 1.257; P = 0.145), and
meta-analysis (coefficient, 0.041; 95% CI, -0.518 to 0.600;
P = 0.882; Table4).
Subgroup analysis
Considering that AMSTAR2 was developed based on
interventional SRs/MAs, we conducted a subgroup
analysis of the 38 included interventional SRs/MAs.
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Guanetal. BMC Medical Research Methodology (2023) 23:281
Table 1 Characteristics of included articles
Study Country
(Region) SRs/MAs Whether CDSR Type of SRs Type of included studies Preregistration PRISMA Funding Disease Sample size
Collins et al. 1999 [33] USA
(North America) SRs CDSR Interventional RCT/Crossover trail/CCT Y N Y CP/CPPS
(III) 600
Collins et al. 2000 [34] USA
(North America) SRs Non-CDSR Interventional RCT/Crossover trail/CCT N N Y CP/CPPS 1954
Collins et al. 2002 [35] USA
(North America) SRs CDSR Interventional RCT Y N Y CP/CPPS
(IIIA/IIIB) 54
Yang et al. 2006 [36] China
(Asia) MAs Non-CDSR Interventional RCT N N N CP/CPPS
(III) 734
Lee et al. 2007 [37] USA
(North America) SRs Non-CDSR Interventional open-label or small pro-
spective studies/ double-
blinded and placebo-con-
trolled clinical trials
N N N CP/CPPS 818
Mishra et al. 2007 [38] UK
(Europe) SRs Non-CDSR Interventional RCT N N N CP/CPPS
(III) 386
Yang et al. 2008 [39] China
(Asia) SRs/MAs Non-CDSR Interventional RCT N N N CP/CPPS 1050
Anothaisintawee et al. 2011
[40]Thailand
(Asia) SRs/MAs Non-CDSR Interventional RCT N N Y CP/CPPS
(IIIA/IIIB) 2021
Aboumarzouk et al. 2012
[41]UK
(Europe) SRs CDSR Interventional RCT Y N Y CP/CPPS
(IIIA/IIIB) 324
Cohen et al. 2012 [42] USA
(North America) SRs/MAs Non-CDSR Interventional RCT N Y N CP/CPPS
(III) 3312
Thakkinstian et al. 2012 [43] Canada
(North America) SRs/MAs Non-CDSR Interventional RCT N N N CP/CPPS
(IIIA/IIIB) 1669
Moldwin et al. 2013 [44] USA
(North America) SRs Non-CDSR Interventional RCT/NRSI N N N CP/CPPS NR
Fu et al. 2014 [45] China
(Asia) SRs/MAs Non-CDSR Non-interventional case–control studies N Y N CP/CPPS 1454
Riegel et al. 2014 [46] Germany
(Europe) SRs Non-CDSR Non-interventional RCT/prospective study/
Retrospective review/Case–
control study/Experimental
study/Evaluation of clinical
data/Longitudinal study/
cohort study
Y Y Y CP/CPPS
(IIIA/IIIB) 44,650
Zhu et al. 2014 [47] China
(Asia) MAs Non-CDSR Interventional RCT N N N CP/CPPS (III) 539
Chen et al. 2015 [48] China
(Asia) SRs/MAs Non-CDSR Non-interventional Case–control studies/
cohort studies/cross-sec-
tional studies
Y Y N CP/CPPS 33,033
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Guanetal. BMC Medical Research Methodology (2023) 23:281
Table 1 (continued)
Study Country
(Region) SRs/MAs Whether CDSR Type of SRs Type of included studies Preregistration PRISMA Funding Disease Sample size
Li et al. 2015 [49] China
(Asia) MAs Non-CDSR Non-interventional Observational studies/
cohort studies/cross-sec-
tional studies/case series
N N N CP/CPPS 11,189
Liu et al. 2016 [50] China
(Asia) SRs/MAs Non-CDSR Interventional RCT N Y N CP/CPPS 754
Qin et al. 2016a [51] China
(Asia) MAs Non-CDSR Interventional RCT N Y N CP/CPPS
(III) 1203
Qin et al. 2016b [52] China
(Asia) SRs/MAs Non-CDSR Interventional RCT Y Y N CP/CPPS (III) 471
Cai et al. 2017 [53] Italy
(Europe) SRs/MAs Non-CDSR Interventional pre-clinical studies/clinical
trials/RCT/cohort studies/
case–control studies
N Y N CP/CPPS 590
Chang et al. 2017 [54] China
(Asia) SRs/MAs Non-CDSR Interventional RCT N Y Y CP/CPPS
(IIIA/IIIB) 502
Anderson et al. 2018 [55] USA
(North America) MAs Non-CDSR Interventional RC T/case series N Y N CP/CPPS 380
Franco et al. 2018 [56] Argentina
(South America) SRs/MAs CDSR Interventional RCT Y Y N CP/CPPS (III) 3290
Franco et al. 2019 [57] Argentina
(South America) SRs/MAs CDSR Interventional RCT Y Y N CP/CPPS
(III) 9119
Liao et al. 2019 [58] China
(Asia) MAs Non-CDSR Interventional RCT N N Y CP/CPPS 838
Qin et al. 2019a [59] China
(Asia) MAs Non-CDSR Interventional RCT/case series N Y Y CP/CPPS 329
Qin et al. 2019b [60] China
(Asia) SRs/MAs Non-CDSR Interventional RCT/case series N Y Y CP/CPPS 439
Yuan et al. 2019 [61] China
(Asia) SRs/MAs Non-CDSR Interventional RCT N N Y CP/CPPS 280
Birowo et al. 2020 [62] Indonesia
(Asia) SRs/MAs Non-CDSR Interventional RCT Y Y Y CP/CPPS 137
Huang et al. 2020 [63] China
(Asia) MAs Non-CDSR Non-interventional cross-sectional studies N Y Y CP/CPPS 1308
Li et al. 2020 [64] China
(Asia) SRs/MAs Non-CDSR Interventional RCT N Y Y CP/CPPS (III) 748
Chen et al. 2021 [65] China
(Asia) SRs/MAs Non-CDSR Non-interventional RCT/NRSI N Y Y CP/CPPS NR
Kang et al. 2021 [66] China
(Asia) MAs Non-CDSR Interventional RCT N Y Y CP/CPPS 525
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Guanetal. BMC Medical Research Methodology (2023) 23:281
Table 1 (continued)
Study Country
(Region) SRs/MAs Whether CDSR Type of SRs Type of included studies Preregistration PRISMA Funding Disease Sample size
Li et al. 2021 [67] China
(Asia) SRs/MAs Non-CDSR Interventional RCT/Non-RCT N Y Y CPPS 317
Mykoniatis et al. 2021 [68] Greece
(Europe) SRs/MAs Non-CDSR Interventional RCT Y Y N CP/CPPS (IIIB) 316
Zhang et al. 2021a [69] China
(Asia) MAs Non-CDSR Interventional RCT N Y Y CP/CPPS
(IIIA/IIIB) 770
Zhang et al. 2021b [70] China
(Asia) MAs Non-CDSR Interventional RCT Y Y Y CP/CPPS with SD 2996
Kong et al. 2022 [71] China
(Asia) SRs/MAs Non-CDSR Interventional RCT Y Y Y CP/CPPS 651
Lao et al. 2022 [72] China
(Asia) SRs/MAs Non-CDSR Interventional RCT Y Y Y CP/CPPS
(IIIA/IIIB) 4244
Lok et al. 2022 [73] China
(Asia) SRs/MAs Non-CDSR Interventional RCT N Y N CP/CPPS 434
Andrey et al. 2022 [6] Russia
(Europe) SRs/MAs Non-CDSR Interventional RCT Y Y N CP/CPPS 5512
Qin et al. 2022a [7] China
(Asia) SRs/MAs Non-CDSR Interventional RCT Y Y Y CP/CPPS 1188
Qin et al. 2022b [74] China
(Asia) SRs/MAs Non-CDSR Interventional RCT Y Y Y CP/CPPS 3514
Zhao et al. 2022 [75] China
(Asia) SRs Non-CDSR Non-interventional RCT/Non-RCT N Y Y CP/CPPS (III) 431
Y yes, N no, NR Not reported, CDSR, Cochrane Database of Systematic Reviews
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Page 9 of 17
Guanetal. BMC Medical Research Methodology (2023) 23:281
Univariate analysis showed that the methodological qual-
ity of interventional SRs/MAs of CP/CPPS was signifi-
cantly associated with the affiliated continent (P = 0.017)
and preregistration (P = 0.014; Table5). However, in mul-
tivariate analysis, only the continent remained signifi-
cant. Specifically, SRs/MAs from Asia had a significant
difference in methodological quality when compared
with SRs/MAs from Europe (coefficient, 0.652; 95% CI,
0.046 to 1.258; P = 0.036), but were similar to those from
North America (coefficient, -0.053; 95% CI, -0.639 to
0.532; P = 0.853) and South America (coefficient, -0.094;
95% CI, -1.233 to 1.045; P = 0.867; Table6).
Sensitivity analysis
As AMSTAR2 was developed in 2017, we performed a
sensitivity analysis to explore the impact of the release of
AMSTAR2 on the methodological quality of SRs/MAs of
CP/CPPS. us, the publication years were changed to
another two categories, that was before 2018 and after
2018 (including 2018). We found no substantial change
in the results of both main and subgroup analysis (Addi-
tional files 6 and 7).
Discussion
In this study, we assessed for the first time the methodo-
logical quality of the SRs/MAs of CP/CPPS. In general,
the methodological quality of SRs/MAs of CP/CPPS was
mostly unsatisfactory.
Although SRs/MAs are considered one of the highest
levels of evidence, their quality varies considerably which
affects their clinical applicability. Sun etal. reported that
the quality of SRs/MAs in traditional Chinese medi-
cine for ischemic stroke is poor, which led to a lack of
timely access to valid information for clinicians [76]. In
our study, a general lack of methodological rigor was
noted in SRs/MAs of CP/CPPS, which might explain
why there was no standardized management strategy
for CP/CPPS until today to some extent. erefore, the
methodological quality of SRs/MAs of CP/CPPS should
be improved. Firstly, to ensure standardization of the
study implementation process and improve the open-
ness, transparency, and reproducibility of the evidence,
researchers should register or publish their study pro-
tocol in advance, which could avoid unnecessary dupli-
cation, reduce finite resources waste, and encourage
cooperation [77]. Secondly, RCTs and observational stud-
ies often have complementary roles [28], and SRs/MAs
might give an incomplete summary when only RCTs are
included [17]. So, we strongly recommend that authors of
SRs/MAs explain their selection of the study designs for
inclusion. irdly, search strategies for SRs/MAs must be
comprehensive and sensitive to ensure the inclusion of all
relevant primary research [78]. However, relevant gray
literature was often overlooked in most included SRs/
MAs. erefore, not only comprehensive search strategy
should be used in the literature search process, but also
gray literature (such as conference papers, and academic
dissertations) should be searched manually. Fourthly, the
lack of a list of excluded literature and the reasons often
indicates less transparency in reporting [78]. us, a list
of exclusions and reasons should be provided to further
improve the rigor of the literature selection process in
future studies. Fifthly, industry-funded studies are more
likely to reach conclusions that benefit the industry [79,
80]. e AMSTAR2 tool added a review of the fund-
ing source for included studies in reviews, but funding
sources and conflicts of interest were seldom reported
in included SRs, which should be improved in the future.
Sixthly, when significant heterogeneity exists, in addi-
tion to correctly applying the random or fixed effect
Fig. 2 Publication year of included studies
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Page 10 of 17
Guanetal. BMC Medical Research Methodology (2023) 23:281
Table 2 Result of the AMSTAR2 assessments
Y yes, PY partial yes, N no, NA not applicable, CL critically low, L low, M moderate
Study AMSTAR-2 Quality
Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Q13 Q14 Q15 Q16
Collins et al. 1999 [33] Y Y N PY Y Y N Y N N NA NA N Y NA Y CL
Collins et al. 2000 [34] Y N N PY N Y N PY N N NA NA N Y NA N CL
Collins et al. 2002 [35] Y N N PY Y Y Y Y N N NA NA N Y NA Y CL
Yang et al. 2006 [36] Y N N PY N N N PY PY N Y N N N N N CL
Lee et al. 2007 [37] Y N N N N N N PY N N NA NA N N NA N CL
Mishra et al. 2007 [38] Y N N PY N N Y Y N N NA NA Y Y NA N CL
Yang et al. 2008 [39] Y N N PY Y Y N PY PY N N N N N N N CL
Anothaisintawee et al. 2011 [40] Y N N PY Y Y N PY Y N Y Y Y Y Y Y CL
Aboumarzouk et al. 2012 [41] Y Y N PY Y Y Y PY Y N NA NA Y Y NA Y M
Cohen et al. 2012 [42] Y N N PY Y Y N Y Y Y Y N N Y Y Y CL
Thakkinstian et al. 2012 [43] Y N N PY N Y N PY N N N N N Y N Y CL
Moldwin et al. 2013 [44] N N N N N N N N N N NA NA N N NA Y CL
Fu et al. 2014 [45] Y N N PY Y Y N Y Y N Y N N Y N Y CL
Riegel et al. 2014 [46] Y PY N PY Y Y N PY N N NA NA Y N NA Y CL
Zhu et al. 2014 [47] Y N N PY N Y N PY Y N Y Y Y Y Y Y CL
Chen et al. 2015 [48] Y PY N PY Y Y Y Y Y N N Y Y Y Y Y L
Li et al. 2015 [49] Y N N PY N Y N Y Y N Y N N N Y Y CL
Liu et al. 2016 [50] Y N N PY Y Y N Y Y N N N N Y N Y CL
Qin et al. 2016a [51] Y N N PY Y Y N PY Y N N N N N N Y CL
Qin et al. 2016b [52 ] Y PY N Y Y Y N PY Y N Y N N Y Y Y CL
Cai et al. 2017 [53] Y N N PY Y Y N PY PY N N Y Y N N Y CL
Chang et al. 2017 [54] Y N N PY Y Y N Y Y N Y N N Y Y Y CL
Anderson et al. 2018 [55] Y N N PY N N N PY N N N N N Y N N CL
Franco et al. 2018 [56] Y Y N PY Y Y Y Y Y Y Y N N Y N Y CL
Franco et al. 2019 [57] Y Y N Y Y Y Y Y Y Y Y N N Y Y Y L
Liao et al. 2019 [58] Y N N PY Y Y N PY Y N N N N Y Y N CL
Qin et al. 2019a [59] Y N N PY Y Y N PY N N N N N N N Y CL
Qin et al. 2019b [60] Y N N PY Y Y N PY N N N N N N N Y CL
Yuan et al. 2019 [61] Y N N PY N N N PY Y N Y N N N N Y CL
Birowo et al. 2020 [62] Y PY N PY Y N N PY Y N N Y Y N N Y CL
Huang et al. 2020 [63] Y N N PY N N N PY N N N N N N Y Y CL
Li et al. 2020 [64] Y N N PY N N N PY Y N N N N N N Y CL
Chen et al. 2021 [65] Y N N PY Y N N PY N N N N N N Y Y CL
Kang et al. 2021 [66] Y N N PY Y Y N PY Y N N N N N Y Y CL
Li et al. 2021 [67] Y N N PY Y Y N PY N N N N N Y N Y CL
Mykoniatis et al. 2021 [68] Y PY N PY Y Y Y PY Y N Y N Y Y Y Y M
Zhang et al. 2021a [69] Y N N PY Y Y N PY PY N Y N N N N Y CL
Zhang et al. 2021b [70] Y PY N N Y Y N PY Y N N N Y N Y Y CL
Kong et al. 2022 [71] Y Y N PY Y Y N PY Y N Y N N N N Y CL
Lao et al. 2022 [72 ] Y PY N PY Y Y N PY Y N Y N Y N Y Y L
Lok et al. 2022 [73] Y N N N Y Y N PY Y N N N N N N Y CL
Andrey et al. 2022 [6] Y PY Y PY Y Y N PY Y N N N N N Y Y CL
Qin et al. 2022a [7] Y PY N PY Y Y N PY Y N Y N N Y N Y CL
Qin et al. 2022b [74] Y Y N PY Y Y N PY Y Y Y N N N N Y CL
Zhao et al. 2022 [75] N N N PY Y Y N N N N NA NA Y N NA Y CL
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Guanetal. BMC Medical Research Methodology (2023) 23:281
model, researchers need to perform subgroup analysis
or meta-regression to analyze the causes of heterogene-
ity and explain its impact on research results. Finally,
while adhering to the relevant guidelines to minimize
bias, researchers should be aware that it is not enough to
assess the risk of bias, but must consider its impact on
the results of the review.
Next, we explored potential factors affecting the meth-
odological quality of SRs/MAs of CP/CPPS. Univariate
analysis showed that the methodological quality of SRs/
MAs of CP/CPPS is significantly associated with con-
tinent and preregistration. Considering that the vast
majority of the SRs/MAs included in the study were
assessed as critically low quality, the probability of esti-
mation of this level of quality is always close to 1 and
does not require fitting an ordered regression model.
erefore, we employed the multivariate linear regres-
sion model with the overall score as the dependent
variable. However, no factors including continent and
preregistration were found significantly associated with
the methodological quality of SRs/MAs of CP/CPPS in
the multivariate analysis. In fact, the study region was
not always classified consistently in published literature.
A study found that there was a significant difference in
reporting and methodologic qualities in published surgi-
cal MAs from Asia and non-Asia [27]. Differently, some
studies did not find the impact of the study region on
the methodological quality of the MAs, in which the
study regions were divided more detailedly [81, 82]. e
impact of the study region on methodological quality of
SRs/MAs of CP/CPPS should be further explored in the
future. Similarly, unlike the results of univariate analysis,
preregistration was also found not to correlate with the
methodological quality in multivariate analysis. is may
be due to the small sample size, which needs to be further
expanded in the future to verify the effect of registra-
tion on the quality of SRs/MAs of CP/CPPS. Preregistra-
tion can ensure a more standardized study process and
help to reduce the selective outcome-reporting bias [83].
Previous studies have shown that preregistration was
independently associated with superior methodological
quality and contributes to the methodological quality of
SRs [27, 84]. erefore, preregistration may be an effec-
tive measure to improve the methodological quality of
SRs and should be taken into account by researchers.
Previous studies have illustrated that the quality of
SRs/MAs tends to improve gradually over time [15, 78,
81, 85]. However, although the vast majority of SRs/
MAs (n = 38, 84.4%) of CP/CPPS were published after
2010, we found that the methodological quality of SRs/
MAs of CP/CPPS did not significantly improve after
2010. e PRISMA statement was developed to pro-
mote transparent and complete reporting of system-
atic reviews [86]. Some researchers found a positive
correlation between AMSTAR and PRISMA scores in
SRs [30, 87]. However, we did not observe the impact
of adhering to PRISMA on the methodological qual-
ity of SRs/MAs of CP/CPPS in this study. Addition-
ally, some studies found that SRs/MAs with conflicts of
interest tend to have lower methodological quality and
reach favorable conclusions than those without finan-
cial conflicts of interest [88, 89]. Ghozy et al. found
that financial support does not significantly affect
the overall quality of SRs which was consistent with
our results, and they found that funded studies tend
to include more RCTs and report conflicts of interest
more frequently than non-funded ones [90]. e reli-
ability of the conclusions of SRs also depends on the
quality of the initial studies included. To compare the
advantages and disadvantages of various interventions,
Fig. 3 Probability of AMSTAR2 response per question
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Page 12 of 17
Guanetal. BMC Medical Research Methodology (2023) 23:281
the best form of evidence is a rigorously designed RCT
with an adequate sample size [91]. RCTs are known to
have the highest quality of evidence of all study types,
which makes them the gold standard for evidence syn-
thesis [28]. However, we did not find the influence of
RCT enrollment on the methodological quality of SRs/
MAs of CP/CPPS in this study which should be fur-
ther validated in the future. Some studies reported that
non-CDSR often had lower statistical precision despite
reporting larger effect sizes than CDSR, which may be
due to the more standardized methodology and more
transparent reporting of Cochrane reviews [23, 92].
However, we did not observe such a difference in our
study. Meta-analysis inclusion in SRs was regarded
as a potential influencing factor in many studies, and
those studies found that SRs with a meta-analysis have
a higher AMSTAR2 score [32, 85]. As a useful tool for
summarizing research evidence, meta-analysis might
not be always applicable because of clinical or statistical
heterogeneity. Our results did not show the association
between the presence of a meta-analysis and meth-
odological quality of SRs of CP/CPPS. It might be that
authors often did not conduct meta-analysis due to sig-
nificant heterogeneity while such a situation might not
affect the final quality of the produced SRs.
Notably, AMSTAR2 was initially used only for SRs/
MAs that include healthcare interventions. Neverthe-
less, in recent years, a considerable number of studies
have tried to use AMSTAR2 for non-interventional
SRs/Mas [15, 93], so we included both intervention
and non-intervention SRs/MAs in our initial analyses.
Subsequently, we conducted a subgroup analysis after
excluding non-interventional SRs/MAs, and the uni-
variate analysis was consistent with the results of the
initial analyses. Differently, in the multivariate analy-
sis of intervention SRs, the continent remained sig-
nificantly associated with the methodological quality
of SRs/MAs of CP/CPPS. Particularly, there were sig-
nificant differences in methodological quality between
SRs/MAs from Asia and Europe. The difference
between the main analysis and the subgroup analysis in
the multivariate analysis might be due to a more strin-
gent classification of the types of SRs which implied
lower heterogeneity. However, due to the small sample
size of this study and the large number of independ-
ent variables included in the regression analysis, these
Table 3 Univariable analysis of potential factors affecting the
methodologic quality of SRs/MAs of CP/CPPS (N = 45)
Percentages may not sum to 100 due to rounding of values
CL critically low, L low, M moderate
Characteristics N (%)
(N = 45) Total (N = 45) P value
M (N = 2) L (N = 3) CL (N = 40)
Publication year 1.000
Before 2010 7 (15.6) 0 (0.0) 0 (0.0) 7 (100.0)
After 2010 38 (84.4) 2 (5.3) 3 (7.9) 33 (86.8)
Continent 0.027
Asia 29 (64.4) 0 (0.0) 2 (6.9) 27 (93.1)
Europe 6 (13.4) 2 (33.3) 0 (0.0) 4 (66.7)
North America 8 (17.8) 0 (0.0) 0 (0.0) 8 (100.0)
South America 2 (4.4) 0 (0.0) 1 (50.0) 1 (50.0)
PRISMA 0.589
No 15 (33.3) 1 (6.7) 0 (0.0) 14 (93.3)
Yes 30 (66.7) 1 (3.3) 3 (10.0) 26 (86.7)
Preregistration 0.004
No 29 (64.4) 0 (0.0) 0 (0.0) 29 (100.0)
Yes 16 (35.6) 2 (12.5) 3 (18.8) 11 (68.8)
Funding support 0.791
No 21 (46.7) 1 (4.8) 2 (9.5) 18 (85.7)
Yes 24 (53.3) 1 (4.2) 1 (4.2) 22 (91.6)
RCT enrollment 0.590
non-RCTs 5 (11.1) 0 (0.0) 1 (20.0) 4 (80.0)
RCTs 29 (64.4) 2 (6.9) 2 (6.9) 25 (86.2)
RCTs and non-RCTs 11 (24.4) 0 (0.0) 0 (0.0) 11 (100.0)
Whether CDSR 0.087
non-CDSR 40 (88.9) 1 (2.5) 2 (5.0) 37 (92.5)
CDSR 5 (11.1) 1 (20.0) 1 (20.0) 3 (60.0)
Meta-analysis 0.431
Without 9 (20.0) 1 (11.1) 0 (0.0) 8 (88.9)
With 36 (80.0) 1 (2.8) 3 (8.3) 32 (88.9)
Table 4 Multiple linear regression analysis of potential factors
affecting the methodologic quality of SRs/MAs of CP/CPPS
(N = 45)
Characteristics Coecients 95% CI P value
Publication year (Before 2010)
After 2010 0.333 -0.159, 0.826 0.177
Continent (Asia)
Europe 0.481 -0.040, 1.002 0.069
North America -0.064 -0.557, 0.429 0.793
South America -0.299 -1.315, 0.718 0.554
PISMA (No)
Yes -0.105 -0.510, 0.300 0.602
Preregistration (No)
Yes 0.231 -0.138, 0.600 0.212
Funding support (No)
Yes -0.059 -0.416, 0.297 0.737
RCT enrollment (non-RCTs)
RCTs and non-RCTs -0.272 -0.808, 0.264 0.309
RCTs -0.176 -0.624, 0.272 0.430
Whether CDSR (non-CDSR)
CDSR 0.532 -0.193, 1.257 0.145
Meta-analysis (Without)
With 0.041 -0.518, 0.600 0.882
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Guanetal. BMC Medical Research Methodology (2023) 23:281
results should be further confirmed. Subsequently, to
further explore whether the methodological quality of
the SRs has improved after the release of AMSTAR, we
used 2018 as the cut-off year in the sensitivity analy-
sis. We reconducted the regression analyses and found
that the results of the analysis did not change substan-
tially. This validated the robustness of the results of
the main and subgroup analysis to some extent.
Study limitations
is study has several limitations. First, although
AMSTAR2 was adopted in this study for the methodology
evaluation of CP/CPPS-related SRs, there is no gold stand-
ard for assessing the quality of SRs. However, AMSTAR2
is one of the most widely used tools for evaluating the
methodology quality of SRs. Second, only SRs/MAs writ-
ten in English or Chinese were included. us, publication
bias might exist. ird, we used VIF to test whether there
is multicollinearity between factors. Although we did
not find multicollinearity, there may be some correla-
tion between individual variables. Fourth, a small sample
of study were considered in this study while a relatively
large number of influencing variables were adopted in the
analysis, which might affect the stability of the results and
require further verification in the future. Fifth, due to limi-
tations in the design of cross-sectional studies, our findings
may not apply to other disease areas of medicine. Finally
and noteworthyly, there were some differences between
the registered protocol and the manuscript. For example,
there were not any restrictions to the publication language
in the protocol while only studies published in Chinese or
English were included in the final manuscript. No publi-
cation language restriction guaranteed the comprehen-
siveness of the conducting literature retrieval. However,
considering the accuracy of translation and data extrac-
tion, and few publications in non-Chinese or non-English
after retrieval, only the Chinese and English documents
were included. Additionally, as stated in the protocol, we
planned to use the PRISMA checklist, the AMSTAR2
tool, the ROBIS tool, and the GRADE system to assess the
quality of CP/CPPS-related SRs comprehensively through
various aspects such as quality of reporting, methodologi-
cal quality, risk of bias, and grading of evidence [94–98].
Also, we intended to assess the clinical efficacy of different
Table 5 Univariable analysis of potential factors affecting the
methodologic quality of interventional SRs/MAs of CP/CPPS
(N = 38)
Percentages may not sum to 100 due to rounding of values
CL critically low, L low, M moderate
Characteristics N (%)
(N = 38) Total (N = 38) P value
M (N = 2) L (N = 2) CL (N = 34)
Publication year 1.000
Before 2010 7 (18.4) 0 (0.0) 0 (0.0) 7 (100.0)
After 2010 31 (81.6) 2 (6.5) 2 (6.5) 27 (87.1)
Continent 0.017
Asia 23 (60.5) 0 (0.0) 1 (4.3) 22 (95.7)
Europe 5 (13.2) 2 (40.0) 0 (0.0) 3 (60.0)
North America 8 (21.1) 0 (0.0) 0 (0.0) 8 (100.0)
South America 2 (5.3) 0 (0.0) 1 (50.0) 1 (50.0)
PRISMA 0.773
No 14 (36.8) 1 (7.1) 0 (0.0) 13 (92.9)
Yes 24 (63.2) 1 (4.2) 2 (8.3) 21 (87.5)
Preregistration 0.014
No 24 (63.2) 0 (0.0) 0 (0.0) 24 (100.0)
Yes 14 (36.8) 2 (14.3) 2 (14.3) 10 (71.4)
Funding support 1.000
No 18 (47.4) 1 (5.6) 1 (5.6) 16 (88.9)
Yes 20 (52.6) 1 (5.0) 1 (5.0) 18 (90.0)
RCT enrollment 1.000
non-RCTs 1 (2.6) 0 (0.0) 0 (0.0) 1 (100.0)
RCTs 29 (76.3) 2 (6.9) 2 (6.9) 25 (86.2)
RCTs and non-RCTs 8 (21.1) 0 (0.0) 0 (0.0) 8 (100.0)
Whether CDSR 0.076
non-CDSR 33 (86.8) 1 (3.0) 1 (3.0) 31 (93.9)
CDSR 5 (13.2) 1 (20.0) 1 (20.0) 3 (60.0)
Meta-analysis 0.574
Without 7 (18.4) 1 (14.3) 0 (0.0) 6 (85.7)
With 31 (81.6) 1 (3.2) 2 (6.5) 28 (90.3)
Table 6 Multiple linear regression analysis of potential factors
affecting the methodologic quality of interventional SRs/MAs of
CP/CPPS (N = 38)
Characteristics Coecients 95% CI P value
Publication year (Before 2010)
After 2010 0.398 -0.149, 0.944 0.147
Continent (Asia)
Europe 0.652 0.046, 1.258 0.036
North America -0.053 -0.639, 0.532 0.853
South America -0.094 -1.233, 1.045 0.867
PRISMA (No)
Yes -0.134 -0.606, 0.338 0.564
Preregistration (No)
Yes 0.194 -0.237, 0.625 0.362
Funding support (No)
Yes 0.029 -0.384, 0.442 0.886
RCT enrollment (non-RCTs)
RCTs and non-RCTs -0.405 -1.470, 0.660 0.441
RCTs -0.322 -1.424, 0.781 0.554
Whether CDSR (non-CDSR)
CDSR 0.425 -0.422, 1.272 0.312
Meta-analysis (Without)
With -0.020 -0.817, 0.776 0.958
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Page 14 of 17
Guanetal. BMC Medical Research Methodology (2023) 23:281
interventions in SRs. However, this is a big project, espe-
cially when there is a lot of clinical efficacy data to evaluate
and grade. us, we only attempted to explore the meth-
odological quality and influencing factors in this prelimi-
nary study utilizing a widely adopted AMSTAR2 tool [17].
Although it seemed to be part of the preconceived study,
this study is an exploratory work while the influencing fac-
tors we explored might be certainly enlightening. Addi-
tionally, it might provide some reference for our follow-up
research to comprehensively evaluate the study quality
and evidence grade about CP/CPPS-related SRs based
on the registered protocol. In short, possible associations
between methodological rigor and review characteristics,
as well as comprehensive methodological features and evi-
dence grading of CP/CPPS-related SRs should be further
explored in the future.
Conclusions
e methodological quality of SRs/MAs of CP/CPPS was
suboptimal, and most were rated as low and critically
low. In addition, this study identified domains where the
methodological quality of SRs/MAs of CP/CPPS could
be improved. Researchers should strictly adhere to the
AMSTAR2 items to improve the methodological quality
of SRs/MAs in the future. Although none of the investi-
gated factors showed the association with the methodo-
logical quality of all types of SRs/MAs of CP/CPPS, the
continent was associated with the methodological quality
of a subgroup of interventional SRs/MAs of CP/CPPS.
Abbreviations
SRs/Mas Systematic reviews/meta-analyses
RCT Randomised controlled trial
CCT Controlled clinical trial
NRSI Non-randomised studies of the effects of interventions
CP/CPPS Chronic prostatitis/chronic pelvic pain syndrome
SD Sexual dysfunction
PRISMA Preferred Reporting Items for systematic review and meta-analysis
AMSTAR A Measurement Tool to Assess systematic Reviews
VIFs Variance inflation factors
CDSR Cochrane Database of Systematic Reviews
Supplementary Information
The online version contains supplementary material available at https:// doi.
org/ 10. 1186/ s12874- 023- 02095-0.
Additional le1.
Additional le2.
Additional le3.
Additional le4.
Additional le5.
Additional le6.
Additional le7.
Acknowledgements
Not applicable.
Authors’ contributions
Conceptualization: XG, YFL, JW, YNW, ZLD. Data curation: YNB, XLL, SL.
Formal analysis: ZWL, FHL. Funding acquisition: ZLD. Investigation: XLL, ZWL.
Methodology: XG, YFL, JW, YNW, YNB, ZLD. Project administration: XG, YFL,
ZLD. Software: XG, YFL, JW, YNW. Supervision: XG, YFL. Validation: XG, YFL, ZLD.
Visualization: XG, YFL, JW. Writing–original draft: XG, YFL, JW, ZLD. Writing –
review & editing: XG, YFL, ZLD.
Funding
This work was supported by the National Natural Science Foundation of China
(Grant No. 82160148), and the Cuiying Scientific Training Program for Under-
graduates of Lanzhou University Second Hospital (Grant No. CYXZ2021-16 and
CYXZ2022-41). The funders had no role in the study design, data collection
and analysis, decision to publish, or preparation of the manuscript.
Availability of data and materials
The data analyzed in this article can all be found within the article text, tables,
figures, and supplementary material.
Declarations
Ethics approval and consent to participate
Not applicable.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Author details
1 Second Clinical Medical College, Lanzhou University, Lanzhou, China.
2 Department of Urology, Lanzhou University Second Hospital, Lanzhou, China.
3 Laboratory Medicine Center, Lanzhou University Second Hospital, Lanzhou,
China.
Received: 8 July 2023 Accepted: 6 November 2023
References
1. Krieger JN, Lee SW, Jeon J, Cheah PY, Liong ML, Riley DE. Epidemiology of
prostatitis. Int J Antimicrob Agents. 2008; 31(Suppl 1):S85–90.
2. Rees J, Abrahams M, Doble A, Cooper A. Diagnosis and treatment of
chronic bacterial prostatitis and chronic prostatitis/chronic pelvic pain
syndrome: a consensus guideline. BJU Int. 2015;116(4):509–25.
3. Zhang J, Liang C, Shang X, Li H. Chronic prostatitis/Chronic pel-
vic pain syndrome: a disease or symptom? Current perspec-
tives on diagnosis, treatment, and prognosis. Am J Mens Health.
2020;14(1):1557988320903200.
4. Krieger JN, Nyberg L Jr, Nickel JC. NIH consensus definition and classifica-
tion of prostatitis. JAMA. 1999;282(3):236–7.
5. Pena VN, Engel N, Gabrielson AT, Rabinowitz MJ, Herati AS. Diagnostic and
management strategies for patients with chronic prostatitis and chronic
pelvic pain syndrome. Drugs Aging. 2021;38(10):845–86.
6. Morozov A, Bazarkin A, Babaevskaya D, Taratkin M, Kozlov V, Suvorov A,
et al. A systematic review and meta-analysis of placebo effect in clinical
trials on chronic prostatitis/chronic pelvic pain syndrome. Prostate.
2022;82(6):633–56.
7. Qin Z, Guo J, Chen H, Wu J. Acupuncture for chronic prostatitis/chronic
pelvic pain syndrome: a GRADE-assessed systematic review and meta-
analysis. European urology open science. 2022;46:55–67.
8. Maeda K, Shigemura K, Fujisawa M. A review of current treatments for
chronic prostatitis/chronic pelvic pain syndrome under the UPOINTS
system. Int J Urol. 2023;30(5):431–6.
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 15 of 17
Guanetal. BMC Medical Research Methodology (2023) 23:281
9. Nickel JC. Chronic prostatitis/chronic pelvic pain syndrome: it is
time to change our management and research strategy. BJU Int.
2020;125(4):479–80.
10. Cai T, Alidjanov J, Palagin I, Medina-Polo J, Nickel JC, Wagenlehner FME.
Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS): look to the
future. Prostate cancer and prostatic diseases. 2023.
11. Horwitz RI, Hayes-Conroy A, Caricchio R, Singer BH. From evidence based
medicine to medicine based evidence. Am J Med. 2017;130(11):1246–50.
12. Zhao M, Gao QH, Liu SJ, Deng YJ, Wang H, Yu WX, et al. Quality
assessment and relevant clinical impact of randomized controlled
trials on chronic prostatitis/chronic pelvic pain syndrome. BMC Urol.
2022;22(1):122.
13. Djulbegovic B, Guyatt GH. Progress in evidence-based medicine: a quar-
ter century on. Lancet (London, England). 2017;390(10092):415–23.
14. Young D. Policymakers, experts review evidence-based medicine. Am J
Health Syst Pharm. 2005;62(4):342–3.
15. Hammel C, Pandis N, Pieper D, Faggion CM Jr. Methodological assess-
ment of systematic reviews of in-vitro dental studies. BMC Med Res
Methodol. 2022;22(1):110.
16. Dong C, Shi H, Liu P, Si G, Yan Z. A critical overview of systematic reviews
and meta-analyses of light therapy for non-seasonal depression. Psychia-
try Res. 2022;314: 114686.
17. Shea BJ, Reeves BC, Wells G, Thuku M, Hamel C, Moran J, et al. AMSTAR 2:
a critical appraisal tool for systematic reviews that include randomised
or non-randomised studies of healthcare interventions, or both. BMJ.
2017;358: j4008.
18. Shea BJ, Grimshaw JM, Wells GA, Boers M, Andersson N, Hamel C, et al.
Development of AMSTAR: a measurement tool to assess the methodo-
logical quality of systematic reviews. BMC Med Res Methodol. 2007;7:10.
19. Whiting P, Savovic J, Higgins JP, Caldwell DM, Reeves BC, Shea B, et al.
ROBIS: a new tool to assess risk of bias in systematic reviews was devel-
oped. J Clin Epidemiol. 2016;69:225–34.
20. Booth A, Clarke M, Dooley G, Ghersi D, Moher D, Petticrew M, et al. The
nuts and bolts of PROSPERO: an international prospective register of
systematic reviews. Syst Rev. 2012;1:2.
21. Page MJ, Shamseer L, Tricco AC. Registration of systematic reviews in
PROSPERO: 30,000 records and counting. Syst Rev. 2018;7(1):32.
22. Yanan Wang YL, Shuai Liu, Xin Guan, Xiaolong Li, Zewen Li, Zhilong Dong.
Methodological quality and clinical outcomes of systematic reviews on
chronic prostatitis/chronic pelvic pain syndrome: an overview: PROS-
PERO 2022 CRD42022343957 Available from: https:// www. crd. york. ac. uk/
prosp ero/ displ ay_ record. php? ID= CRD42 02234 3957; 2022.
23. Moseley AM, Elkins MR, Herbert RD, Maher CG, Sherrington C. Cochrane
reviews used more rigorous methods than non-Cochrane reviews:
survey of systematic reviews in physiotherapy. J Clin Epidemiol.
2009;62(10):1021–30.
24. Aromataris E, Fernandez R, Godfrey CM, Holly C, Khalil H, Tungpunkom P.
Summarizing systematic reviews: methodological development, conduct
and reporting of an umbrella review approach. Int J Evid Based Healthc.
2015;13(3):132–40.
25. Cumpston M, Li T, Page MJ, Chandler J, Welch VA, Higgins JP, et al.
Updated guidance for trusted systematic reviews: a new edition of the
Cochrane Handbook for Systematic Reviews of Interventions. Cochrane
Database Syst Rev. 2019;10(10):ED000142.
26. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JPA,
et al. The PRISMA statement for reporting systematic reviews and meta-
analyses of studies that evaluate health care interventions: explanation
and elaboration. PLoS Med. 2009;6(7): e1000100.
27. Zhang H, Han J, Zhu YB, Lau WY, Schwartz ME, Xie GQ, et al. Reporting
and methodological qualities of published surgical meta-analyses. J Clin
Epidemiol. 2016;70:4–16.
28. Barton S. Which clinical studies provide the best evidence? The best
RCT still trumps the best observational study. BMJ (Clinical research ed).
2000;321(7256):255–6.
29. Sideri S, Papageorgiou SN, Eliades T. Registration in the international pro-
spective register of systematic reviews (PROSPERO) of systematic review
protocols was associated with increased review quality. J Clin Epidemiol.
2018;100:103–10.
30. Ross A, Rankin J, Beaman J, Murray K, Sinnett P, Riddle R, et al. Meth-
odological quality of systematic reviews referenced in clinical practice
guidelines for the treatment of opioid use disorder. PLoS One. 2017;12(8).
31. Pieper D, Hellbrecht I, Zhao L, Baur C, Pick G, Schneider S, et al. Impact of
industry sponsorship on the quality of systematic reviews of vaccines: a
cross-sectional analysis of studies published from 2016 to 2019. Syst Rev.
2022;11(1):174.
32. Sun X, Wang D, Wang M, Li H, Liu B. The reporting and methodological
quality of systematic reviews and meta-analyses of nursing interventions
for chronic obstructive pulmonary disease - A systematic review. Nurs
Open. 2021;8(3):1489–500.
33. McNaughton C, Mac Donald R, Wilt T. Interventions for chronic abacterial
prostatitis. Cochrane Database Syst Rev. 2001;1999(1):Cd002080.
34. McNaughton Collins M, MacDonald R, Wilt TJ. Diagnosis and treatment
of chronic abacterial prostatitis: a systematic review. Ann Intern Med.
2000;133(5):367–81.
35. McNaughton CO, Wilt T. Allopurinol for chronic prostatitis. Cochrane
Database Syst Rev. 2002(4):Cd001041.
36. Yang G, Wei Q, Li H, Yang Y, Zhang S, Dong Q. The effect of alpha-
adrenergic antagonists in chronic prostatitis/chronic pelvic pain
syndrome: a meta-analysis of randomized controlled trials. J Androl.
2006;27(6):847–52.
37. Lee SW, Liong ML, Yuen KH, Liong YV, Krieger JN. Chronic prostatitis/
chronic pelvic pain syndrome: role of alpha blocker therapy. Urol Int.
2007;78(2):97–105.
38. Mishra VC, Browne J, Emberton M. Role of alpha-blockers in type III pros-
tatitis: a systematic review of the literature. J Urol. 2007;177(1):25–30.
39. Yang GM, Zhao XK, Kou Y. Management of chronic prostatitis/chronic
pelvic pain syndrome (CP/CPPS): a systematic review and meta-analysis
of randomized controlled trials (RCTs). Chinese J Androl. 2008;04:20–6.
40. Anothaisintawee T, Attia J, Nickel JC, Thammakraisorn S, Numthavaj
P, McEvoy M, et al. Management of chronic prostatitis/chronic pelvic
pain syndrome: a systematic review and network meta-analysis. JAMA.
2011;305(1):78–86.
41. Aboumarzouk OM, Nelson RL. Pregabalin for chronic prostatitis. Cochrane
Database Syst Rev. 2012(8):Cd009063.
42. Cohen JM, Fagin AP, Hariton E, Niska JR, Pierce MW, Kuriyama A, et al.
Therapeutic intervention for chronic prostatitis/chronic pelvic pain
syndrome (CP/CPPS): a systematic review and meta-analysis. PLoS ONE.
2012;7(8): e41941.
43. Thakkinstian A, Attia J, Anothaisintawee T, Nickel JC. α-blockers, antibiot-
ics and anti-inflammatories have a role in the management of chronic
prostatitis/chronic pelvic pain syndrome. BJU Int. 2012;110(7):1014–22.
44. Herati AS, Moldwin RM. Alternative therapies in the management
of chronic prostatitis/chronic pelvic pain syndrome. World J Urol.
2013;31(4):761–6.
45. Fu W, Zhou Z, Liu S, Li Q, Yao J, Li W, et al. The effect of chronic prostatitis/
chronic pelvic pain syndrome (CP/CPPS) on semen parameters in human
males: a systematic review and meta-analysis. PLoS One. 2014;9(4).
46. Riegel B, Bruenahl CA, Ahyai S, Bingel U, Fisch M, Löwe B. Assessing psy-
chological factors, social aspects and psychiatric co-morbidity associated
with Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) in men
– a systematic review. J Psychosom Res. 2014;77(5):333–50.
47. Zhu Y, Wang C, Pang X, Li F, Chen W, Tan W. Antibiotics are not beneficial
in the management of category III prostatitis: a meta analysis. Urol J.
2014;11(2):1377–85.
48. Chen X, Zhou Z, Qiu X, Wang B, Dai J. The effect of chronic Prostatitis/
Chronic Pelvic Pain Syndrome (CP/CPPS) on erectile function: a system-
atic review and meta-analysis. PLoS ONE. 2015;10(10).
49. Li HJ, Kang DY. Prevalence of sexual dysfunction in men with chronic
prostatitis/chronic pelvic pain syndrome: a meta-analysis. World J Urol.
2016;34(7):1009–17.
50. Liu BP, Wang YT, Chen SD. Effect of acupuncture on clinical symptoms
and laboratory indicators for chronic prostatitis/chronic pelvic pain
syndrome: a systematic review and meta-analysis. Int Urol Nephrol.
2016;48(12):1977–91.
51. Qin Z, Wu J, Tian J, Zhou J, Liu Y, Liu Z. Network Meta-Analysis of the
Efficacy of Acupuncture, Alpha-blockers and Antibiotics on Chronic
Prostatitis/Chronic Pelvic Pain Syndrome. Sci Rep. 2016;6:35737.
52. Qin Z, Wu J, Zhou J, Liu Z. Systematic Review of Acupuncture for Chronic
Prostatitis/Chronic Pelvic Pain Syndrome. Medicine. 2016;95(11): e3095.
53. Cai T, Verze P, La Rocca R, Anceschi U, De Nunzio C, Mirone V. The role
of flower pollen extract in managing patients affected by chronic
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 16 of 17
Guanetal. BMC Medical Research Methodology (2023) 23:281
prostatitis/chronic pelvic pain syndrome: a comprehensive analysis of all
published clinical trials. BMC Urol. 2017;17(1):32.
54. Chang SC, Hsu CH, Hsu CK, Yang SS, Chang SJ. The efficacy of acupunc-
ture in managing patients with chronic prostatitis/chronic pelvic pain
syndrome: a systemic review and meta-analysis. Neurourol Urodyn.
2017;36(2):474–81.
55. Anderson RU, Wise D, Nathanson BH. Chronic Prostatitis and/or Chronic
Pelvic Pain as a Psychoneuromuscular Disorder-A Meta-analysis. Urology.
2018;120:23–9.
56. Franco JV, Turk T, Jung JH, Xiao YT, Iakhno S, Garrote V, et al. Non-pharma-
cological interventions for treating chronic prostatitis/chronic pelvic pain
syndrome. Cochrane Database Syst Rev. 2018;1(1):Cd012551.
57. Franco JV, Turk T, Jung JH, Xiao YT, Iakhno S, Tirapegui FI, et al. Pharmaco-
logical interventions for treating chronic prostatitis/chronic pelvic pain
syndrome. Cochrane Database Syst Rev. 2019;10(10):Cd012552.
58. Liao B, Mou XX, Liu JB, Wu T, Cui S. [Extracorporeal shock wave therapy for
chronic prostatitis / chronic pelvic pain syndrome: a meta-analysis]. Natl J
Androl. 2019;25(10):914–22.
59. Qin Z, Wu J, Xu C, Liu Z. Using meta-regression approach to explore the
dose-response association between acupuncture sessions and acupunc-
ture effects on chronic prostatitis/chronic pelvic pain syndrome. Ann
Transl Med. 2019;7(6):116.
60. Qin Z, Wu J, Xu C, Sang X, Li X, Huang G, et al. Long-term effects of acu-
puncture for chronic prostatitis/chronic pelvic pain syndrome: systematic
review and single-arm meta-analyses. Ann Transl Med. 2019;7(6):113.
61. Yuan P, Ma D, Zhang Y, Gao X, Liu Z, Li R, et al. Efficacy of low-intensity
extracorporeal shock wave therapy for the treatment of chronic prostati-
tis/chronic pelvic pain syndrome: a systematic review and meta-analysis.
Neurourol Urodyn. 2019;38(6):1457–66.
62. Birowo P, Rangganata E, Rasyid N, Atmoko W. Efficacy and safety of extra-
corporeal shockwave therapy for the treatment of chronic non-bacterial
prostatitis: a systematic review and meta-analysis. PLoS One. 2020;15(12).
63. Huang X, Qin Z, Cui H, Chen J, Liu T, Zhu Y, et al. Psychological fac-
tors and pain catastrophizing in men with chronic prostatitis/chronic
pelvic pain syndrome (CP/CPPS): a meta-analysis. Transl Androl Urol.
2020;9(2):485–93.
64. Li J, Dong L, Yan X, Liu X, Li Y, Yu X, et al. Is acupuncture another good
choice for physicians in the treatment of chronic Prostatitis/Chronic
Pelvic Pain Syndrome? Review of the latest literature. Pain Res Manage.
2020;2020:5921038.
65. Chen L, Bian Z, Chen J, Meng J, Zhang M, Liang C. Immunological altera-
tions in patients with chronic prostatitis/chronic pelvic pain syndrome
and experimental autoimmune prostatitis model: a systematic review
and meta-analysis. Cytokine. 2021;141.
66. Kang Y, Song P, Cao D, Di X, Lu Y, Liu P, et al. The efficacy and safety
of extracorporeal shockwave therapy versus acupuncture in the
management of Chronic Prostatitis/Chronic Pelvic Pain Syndrome:
evidence based on a network meta-analysis. Am J Mens Health.
2021;15(6):15579883211057998.
67. Li G, Man L. Low-intensity extracorporeal shock wave therapy for male
chronic pelvic pain syndrome: a systematic review and meta-analysis.
Transl Androl Urol. 2021;10(3):1202–11.
68. Mykoniatis I, Pyrgidis N, Sokolakis I, Sountoulides P, Hatzichristodoulou G,
Apostolidis A, et al. Low-intensity shockwave therapy for the manage-
ment of chronic prostatitis/chronic pelvic pain syndrome: a systematic
review and meta-analysis. BJU Int. 2021;128(2):144–52.
69. Zhang W, Fang Y, Shi M, Zhang M, Chen Y, Zhou T. Optimal acupoint and
session of acupuncture for patients with chronic prostatitis/chronic pel-
vic pain syndrome: a meta-analysis. Transl Androl Urol. 2021;10(1):143–53.
70. Zhang Y, Ma H, Nan T, Li Y, Zheng W, Zhou Z, et al. Comparative efficacy of
oral Chinese patent medicine for chronic Prostatitis/Chronic Pelvic Pain
syndrome with sexual dysfunction: a Bayesian network meta-analysis of
randomized controlled trials. Front Pharmacol. 2021;12.
71. Kong X, Hu W, Dong Z, Tian J, Wang Y, Jin C, et al. The efficacy and safety
of low-intensity extracorporeal shock wave treatment combined with or
without medications in Chronic Prostatitis/Chronic Pelvic pain syndrome:
a systematic review and meta-analysis. Prostate Cancer Prostat Dis. 2022.
72. Lao Y, He L, Zhang P, Dong Z. Efficacy and safety of selective serotonin
re-uptake inhibitors for chronic prostatitis/chronic pelvic pain syn-
drome: a systematic review and network meta-analysis. Asian J Surg.
2022;45(12):2810–2.
73. Lok W, Lin T, Cao D, Wei Q. Is Serenoa repens effective for the treatment of
chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS)? A systematic
review and meta-analysis. Asian J Surg. 2022;45(9):1746–7.
74. Qin Z, Zhang C, Guo J, Kwong JSW, Li X, Pang R, et al. Oral pharmacologi-
cal treatments for chronic prostatitis/chronic pelvic pain syndrome: a
systematic review and network meta-analysis of randomised controlled
trials. EClinicalMedicine. 2022;48.
75. Zhao Y, Lin J, Dong Y, Tian Z, Ye Y, Ma Z, et al. Neuroimaging studies of
Chronic Prostatitis/Chronic pelvic pain syndrome. Pain Res Manage.
2022;2022:9448620.
76. Sun S, Zhao L, Zhou X, Liu X, Xie Z, Ren J, et al. Methodological, reporting,
and evidence quality of systematic reviews of traditional Chinese medi-
cine for ischemic stroke. Front Pharmacol. 2023;14:1047650.
77. Ioannidis JP, Greenland S, Hlatky MA, Khoury MJ, Macleod MR, Moher D,
et al. Increasing value and reducing waste in research design, conduct,
and analysis. Lancet (London, England). 2014;383(9912):166–75.
78. Tumeh RA, Neto MS, Sales GD, Ferreira LM. Quality regarding the
systematic reviews in breast plastic surgery. Aesthetic Plast Surg.
2023;47(2):559–67.
79. Chartres N, Fabbri A, Bero LA. Association of industry sponsorship with
outcomes of nutrition studies: a systematic review and meta-analysis.
JAMA Intern Med. 2016;176(12):1769–77.
80. Lexchin J, Bero LA, Djulbegovic B, Clark O. Pharmaceutical industry
sponsorship and research outcome and quality: systematic review. BMJ
(Clinical research ed). 2003;326(7400):1167–70.
81. Yan P, Yao L, Li H, Zhang M, Xun Y, Li M, et al. The methodological quality
of robotic surgical meta-analyses needed to be improved: a cross-sec-
tional study. J Clin Epidemiol. 2019;109:20–9.
82. Tian J, Zhang J, Ge L, Yang K, Song F. The methodological and reporting
quality of systematic reviews from China and the USA are similar. J Clin
Epidemiol. 2017;85:50–8.
83. Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for
systematic reviews and meta-analyses: the PRISMA statement. BMJ (Clini-
cal research ed). 2009;339: b2535.
84. Ge L, Tian JH, Li YN, Pan JX, Li G, Wei D, et al. Association between pro-
spective registration and overall reporting and methodological quality
of systematic reviews: a meta-epidemiological study. J Clin Epidemiol.
2018;93:45–55.
85. La Torre G, Bova R, Cocchiara RA, Sestili C, Tagliaferri A, Maggiacomo S,
et al. What are the determinants of the quality of systematic reviews in
the international journals of occupational medicine? A methodologi-
cal study review of published literature. Int J Environ Res Public Health.
2023;20(2):1644.
86. Page MJ, Moher D, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD,
et al. PRISMA 2020 explanation and elaboration: updated guidance and
exemplars for reporting systematic reviews. BMJ (Clinical research ed).
2021;372: n160.
87. Yuan M, Wu J, Austin RE, Hofer SOP, Lista F, Ahmad J. Evaluating Breast
Reconstruction Reviews Using A Measurement Tool to Assess Systematic
Reviews (AMSTAR). Plast Reconstr Surg Glob Open. 2021;9(11): e3897.
88. Hansen C, Lundh A, Rasmussen K, Hróbjartsson A. Financial conflicts of
interest in systematic reviews: associations with results, conclusions, and
methodological quality. The Cochrane database of systematic reviews.
2019;8(8):Mr000047.
89. Lundh A, Lexchin J, Mintzes B, Schroll JB, Bero L. Industry sponsorship and
research outcome. Cochrane Database Syst Rev. 2017;2(2):Mr000033.
90. Ghozy S, El-Qushayri AE, Gbreel MI, Farahat RA, Azzam AY, Elfil M, et al. The
impact of funding on the quality and interpretation of systematic reviews
of mechanical thrombectomy in stroke patients. Int Neuroradiology.
2022:15910199221145741.
91. Askie L, Offringa M. Systematic reviews and meta-analysis. Semin Fetal
Neonatal Med. 2015;20(6):403–9.
92. Useem J, Brennan A, LaValley M, Vickery M, Ameli O, Reinen N, et al. Sys-
tematic differences between cochrane and non-cochrane meta-analyses
on the same topic: a matched pair analysis. PLoS One. 2015;10(12).
93. Luo J, Chen Z, Liu D, Li H, He S, Zeng L, et al. Methodological quality and
reporting quality of COVID-19 living systematic review: a cross-sectional
study. BMC Med Res Methodol. 2023;23(1):175.
94. Gomez-Garcia F, Ruano J, Gay-Mimbrera J, Aguilar-Luque M, Sanz-
Cabanillas JL, Alcalde-Mellado P, et al. Most systematic reviews of high
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 17 of 17
Guanetal. BMC Medical Research Methodology (2023) 23:281
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